Steam drying apparatus



June 7, 1949. M sc STEAM DRYING AfPARATUS Filed Jan. 24, 1941 INVENTORWeen/v F/sc ATTORNEY Patented June 7, 1949 UNITED STATES PATENT OFFICE"Martin Frisch, New Yor Wheeler Corporation, New

k, N. Y.,as'signor to Foster poration of New York Application January24, 1941;Ser'ia'l'No. 375,735 1 Claim. (01. 183-109) This inventionrelates to steam generators and pertains to the purification of thesteam generated therein. *More particularly, the invention providesnovel means for removing entrained circulating water from the steam anddrying the steam.

In one form of the invention, the circulation of the --steam generatorisarranged so that all the steam-generated-is-delivered to one of aplurality of upper'drums inwhich novel means are employed for separatingwater from the steam released in the "drum, both above and below thewater level therein. From thisdrum, the separated steamand relativelysteam-free-waterpass through separate groups of circulator tubes to asecond upper drum which is otherwise connected with the circulatorysystem o'f'the unit only by downcomer tubes. The steam entering thesecond drum, flows through :a novel steam washer inwhich any of theoriginally entrained moisture remaining in'the steam, and'whichordinarily has a high concentration'of-solids,will be removed byireshfeed water of a relatively low solid concentration. Thereafter thewashed steam is dried by passing it through a novel drying device beforeleaving the drum. 'It' willbeunderstood that the invention-is notlimited to this particular multidru-marra-ngement. Apparatusembodyingtheinvention may be employed in only one upper drum, and in this case oneor-more ofthe steam purifying steps referred toma'y be omitted ifdesired, depending upon the operating conditions'a'nd requirements of'agiveninstallation.

The invention will be understoodfrom the followingdescr-iptionwheneconsidered in connection with the accompanyingidrawingsforming a part thereof, and in which:

Fig. 1 is a vertical sectional view of an upper portionof a steamgenerator embodying one form of the inventiomand Fig.2 is-a f-ragme Itary section'view inperspective of a steam drying-device of theinvention taken on the line-2-'2 of- Like characters of reference referto the same or to similarpartsineboth of the views.

Referring to-the drawings, the steam-generator illustrated has two uppersteamand 'water drums Hand 12. Connected-t thedrum H'rboth above andbelow the normal'water level therein, are steam generating orrisertubesiS, and extending from the drum l l'to the drum l2 are groupsof steam circulating and water circulating tubes l4 and i5 respectively.CIOnneCted toithe lower portion of the drum III 'are 'downcomer tubesl6, while other downcomer tubes :11 arezconnected to the lower portion:ofwthe zdrum' l2.

York, N. Y., a cor- Within the drum as shown in Fig. l, is dewateringapparatus which dewaters the steam and water mixture discharged by tubes[3 into said drum. 'Such' apparatus does not form a part of thepresentinvention but is included to-merely illustrate a for-m of steamgenerator having an improved boiler circulation due to an increaseddensity of water entering the water-circulators.

T In the drum i2, the'steam delivered thereto by the circulators Hi issubjected to a'washingaction ina steam washer of the general typedisclosed in applicants United States Patent No. 2,380,424, granted July'31, 1945, generally designated23. As illus'trated in Fig. 1 of thedrawings, the steam washer comprises a plurality of horizontallyextending, vertically spaced, generally V-shaped trough members 7. 5which extend longitudinally of the drum l2. 'Each trough member 24baserelatively short flange 25 which extends downwardly and outwardlyfrom the upper end of the leg thereof which is remote from the steamcirculators M. The upper edge of the leg of each trough member havingthe flange '25 may be disposed at the same elevation or at asomewhatlower elevation than the upper edge of the other leg'of-the troughmember. Thetrough members are disposed in nested, but spaced,relationship with the lower edge of each, excepting the lowermost,located at an elevation lower than the upper edges-of the trough memberimmediately below. The flange .25 is sufficiently long to causethe'steam leaving the washer to change its direction of-iflow'abruptlyto eliminate as muchias possible-aof the'wa-ter entrained in the steam.The troughs 2d :are supported by a plurality of spaced, verticallyextending stand pipes 26 which 'are'conheated :at their lower ends tothe horizontally ext'endingportion of a 'feed water inlet-conduit '21.As shownythe stand pipes 26 pass through openings in the trough-membersand they are provided with-discharge orifices28 located just above thelower ends of the troughs. Fresh feed water is supplied throughpipe'z'l' at suchpressure inexcess of'the drum pressure as will fill-thestand pipes 26 and flow into the trough members-'24 through the orifices8. The water will fill the troughs and will flow over the flanged upperedges of the troughs as will presently appear.

' Steam drying means are located adjacent the steam washer 23 in thedrum l2. Asshown, such means comprise a row of separate, spacedV-s'haped plates 29 adjacent but spaced from the washer, "and two rows"of separate, spaced 1V- s'haped plates sll adjacent but spaced fromeach otherand the plates .2 9. The included acute angle to the loweredge between the legs of the plates 30 is smaller than the equivalentangle of the plates 29, as clearly indicated in Fig. 2. The plates 29and 30 are disposed with their edges vertical and with the plates ofeach row in nested, but spaced, relationship as shown, with the edge atthe apex of the angle of each plate located within the area defined bthe next adjacent plate. The number of rows of drying plates utilizedwill depend upon the extent to which the steam is to be dried.

Beyond the drying means in the drum in the direction of flow of thesteam, is a relatively dry steam space 31, from which the steam flowsthrough apertures 32 in a vertically disposed distributing plate 33which extends longitudinally of the drum in the upper portion thereof.Secured of the plate 33 is a horizontally inclined plate 34, which withthe plate 33 and the inner wall of the drum forms a dry steam chamber34' from which purified steam enters one or more outlet nozzles orsuperheater connections 35.

The steam washer 23 and the several rows of drying plates 01' watereliminators 29 and 30, are suitably supported at their upper ends by aplate 39 which is secured to the inner wall of the drum. At their lowerends the drying plates are supported by a horizontal plate 40, which isdisposed a substantial distance below the normal drum water level, thuseffecting a seal. A vertical plate M which extends from the feed waterinlet conduit 2'! to a point just below the trough members 24 preventssteam from flowing below the washer. A skirt baffie 42 which extendsdownwardly from the inner edge of support plate 49, causes thecirculating water entering the drum through circulators E to flowtowards the inlets of the downcomers H. The assembly of the steamwashing and steam drying devices is enclosed adjacent each end of thedrum by vertical closure plates 43, one of which is shown in Fig. 1, toprevent the by-passing of steam entering the drum l2, around either endof the washing and drying assembly.

In operation, the steam and water mixture entering the drum M will bedewatered in said drum, the separated water flowing through thecirculators I5 to the water space of drum [2, while the dewatered steamwill flow from the steam space 36 in the drum II through the circulatorsM to the steam space 38 in the drum I2.

From the steam space 38, the steam enters the washer 23 and flowstherethrough and into the space between the washer and the first row ofdrier plates 29. The submerged apex of each trough member 24 will forcethe steam in the space 33 to flow downwardly into the water in thetrough below. The fresh feed water delivered to the washer troughsthrough the apertures 28 in the stand pipes, is discharged from theseapertures at a relatively high velocity with the result that the waterin the washer troughs normally is not quiescent. Due to the fact thatthe washer extends substantially from the water level to the upper wallof the drum and for at least the greater part of the length of the drum,a large flow area is provided over which the steam may enter the washertroughs, so that the velocity of flow of the steam through the washerwill be relatively low. Thus the time of contact of the steam with thefresh feed water will be relatively long, and the somewhat highervelocity of the steam in passing through the troughs as compared withthe velocity in the steam space 38, will provide thorough contactbetween the steam and water and an adequate washing of the steam. Theflow of steam through the washer will cause the water to flow from thewasher over the flanged upper edges of the troughs and downwardly intothe water in the lower part of the drum. The steam leaving the water inthe troughs will impinge against the flanges 25 and will be forced tochange its direction of flow abruptly from an upwardly inclined to adownwardly inclined direction, thus eliminating a substantial quantityof the water entrained in the steam. This eliminated water will flowdownwardly into the water in the bottom of the drum. As the steam entersthe space between the washer and the drier plates 29, the velocity ofthe steam is reduced due to the increase in the area available for thepassage of the steam, and entrained water will drop out of the steam bygravity in this space before the steam enters the drier.

The washed steam flows into and through the passages between the dryingplates 29, and in its flow through these passages, it is forced tochange its direction of flow abruptly upon entering these passages andalso in the zone between the aplces of the plates, The entrained waterwill impinge upon and be deposited on the plates 29 in the areasadjoining the zones where the abrupt changes in direction of flow occur,and this water will drain down the plates without being re-entrained inthe steam, due to the relatively low velocity of the steam through thedrier and to the cohesive properties of the water and its adherence tothe surfaces of the plates. The steam leaving the passages between theplates 29, flows into the space between the plates 29 and the ad- 30,and in this space water will drop out of the steam by gravity.Thereafter the steam flows into and through the passages between thefirst row of plates 30, into the space between the rows of plates 30,and into and through the passages between the second row 30. EntrainedWater will be eliminated in the same manner as described in connectionplates 29 and the space between the washer and the drier plates 29, theonly differthe steam flowing horizontally and the water drainingdownwardly to the of the drum.

From the second row of drying plates steam flows into steam space 3| itsdirection of entrained moisture, and thence through the oriflces 32 inthe distributing plate 33 into the dry steam space 34. In flowingthrough the plate 33, entrained moisture will impinge against the plateand will be removed from the steam. The distributing plate 33 causes thesteam to be withdrawn from the steam space 3| substantially uniformlyover the length of this space, and insures that the steam leaving thewashers 23 will be dis- 39, the where it changes nozzles or superheaterconnections 35.

With steam washers and with the driers embodying the invention, thevelocity of the steam through and between these devices will be of theorder of magnitude of from one to three feet per second. A satisfactorywasher for the purpose will be composed of troughs having a width of twoinches between the outer ends of the legs, and a height (apex to baseline) of two inches, and With the troughs spaced on a pitch of one inch.The drier plates 29 may have a width of two inches between the outeredges of the legs, and a depth (horizontal distance from apex to baseline) of three inches. The drier plates 30 may be the same as the plates29 excepting that their width will be one inch. The drier plates 29 and30 may be spaced on a pitch of one and one half inches. It will beunderstood that these dimensions are given by way of example and are notto be construed as limiting the invention because other sizes of washertroughs and drier plates arranged on difierent pitches may be employed.

It will be understood that changes may be made in the form location andrelative arrangement of the several parts of the apparatus disclosedherein without departing from the principles of the invention. Forexample, any one instrumentality such as the dewatering channels, theweir and apertured plate, the washer, or the drier, may be employed inthe purification of steam alone or in combination with one or more ofthe other instrumentalities. In view thereof, it will be apparent thatthe invention is not to be limited excepting by the scope of theappended claim.

What is claimed is:

In steam generating apparatus having a drum and means for introducingsteam into the drum, and means for drying the steam in the drumcomprising a plurality of spaced, substantially parallel rows ofseparate vertically extending V- shaped plates horizontally spaced, withthe apex edge or one plate within the area bounded by the next adjacentplate in the same row, the included angle between the legs of the platesin one row being different from the corresponding angle of the plates ofanother row, the plates being disposed in the drum so that the steam tobe dried flows in a substantially horizontal direction through thepassages between the plates.

MARTIN FRISCH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 973,541 Miyabara Oct. 25, 19101,432,721 Naismith Oct. 17, 1922 1,767,020 Smith June 24, 1930 1,822,151Kerr Sept. 8, 1931 1,845,106 Wood Feb. 16, 1932 1,883,380 Kerr et al.Oct. 18, 1932 1,896,656 Anderson Feb. 7, 1933 1,946,248 Weigel Feb. 6,1934 2,016,556 Powell et al. Oct. 8, 1935 2,050,615 Kuhner Aug. 11, 19362,055,781 Angermueller Sept. 29, 1936 2,058,239 Kerr Oct. 20, 19362,058,240 Hobbs Oct. 20, 1936 2,070,067 Rice Feb. 9, 1937 2,075,059Rosencrants et al. Mar. 30, 1937 2,127,917 Hobbs Aug. 23, 1938 2,143,191Fletcher et a1 Jan. 10, 1939 2,194,698 Fletcher Mar. 26, 1940 2,232,265Place Feb. 18, 1941

